I have a 11 or 12 year old craftsman riding mower, model #917.273011, serial #072998C 003468, 20hp kohler pro, 6 speed, with 46" deck. I was cutting grass and the blades just quit going around. I can start it but as soon as I let the clutch out, it dies. And if I pull the pto button out, it dies. I don't get it, what would the clutch and pto have in common ?? I was wondering if there is some kind of switch that is going bad, or is my pto going bad ?? HELP